1. Field of the Invention
The present invention relates to a portable terminal, and more particularly to a hinge apparatus for a portable terminal, which can couple a pair of housings to each other, thereby allowing one of the housings to rotate in a direction of approaching or withdrawing from the other housing while they face each other.
2. Description of the Related Art
In general, portable terminals may be classified into various types according to their appearance, such as a bar-type portable terminal, a flip-type portable terminal, and a folder-type portable terminal.
The bar-type portable terminal has a single body housing on which a data input/output unit, a transmitter, and a receiver are mounted. A keypad used as the data input/output unit always is exposed to the outside and may result in the malfunction thereof. Further, there is limitation in the miniaturization of the portable terminal because it is difficult to secure a sufficient distance between the transmitter and receiver.
The flip-type portable terminal has a body, a flip, and a hinge module for connecting the flip to the body. The body includes a data input/output unit, a transmitter, and a receiver mounted thereon. The flip covers the keypad used as the data input unit so as to prevent the malfunction of the keypad. However, there is also a limitation in the miniaturization of the flip type portable terminal because it is difficult to secure a sufficient distance between the transmitter and the receiver.
The folder-type portable terminal includes a body, a folder, and a hinge apparatus for rotatably connecting the folder to the body, in which the folder rotates to open and close the body. In a communication-standby mode in which the folder is closed over the body, it is possible to prevent the malfunction of the keypad. In a communication mode, as a transmitter and a receiver are arranged on the body and the folder, respectively, it is possible to secure a sufficient distance between the transmitter and the receiver. Thus, there is an advantage of miniaturizing the portable terminal.
U.S. Pat. No. 6,292,980 discloses a hinge apparatus for a portable terminal as described above. The principle of the hinge apparatus disclosed in the U.S. patent is that a hinge cam having mountain-shaped portions and valley-shaped portions, a hinge shaft, and a coil spring enabling the hinge cam to be in close contact with the hinge shaft are received in a hinge housing, thereby opening and closing a folder or a flip using curved surfaces of the mountain-shaped and valley-shaped portions and the elasticity of the coil spring.
Further, such a flip-type or folder-type portable terminal detects the opening and closed states of the flip or folder. As a result, the portable terminal interrupts operation of input/output units such as a keypad, a transmitter, a receiver, and a display unit, etc when the flip or folder is closed. conversely, the portable terminal activates the input/output units to allow voice communication, wireless access to Internet, and data input, etc, when the flip or folder is open.
Meanwhile, in the conventional art, a hall sensor has been used as means for detecting the opening and closed states of the flip or folder. The hall sensor is a magnetic sensor in which resistance varies according to the change of magnetic field. When the portable terminal is open, the hall sensor is located far from a magnetic body, and detects the change of magnetic force so as to interrupt or activate the operation of the input/output units.
However, since the conventional portable terminals have separate detection means, such as a hall sensor, in order to detect the opening and closed states of the flip or folder, an internal circuit has a complicated configuration. Further, since a separate space should be secured in order to mount the hall sensor, there is a limitation to the miniaturization of the portable terminal.